Heart rate reading glitch?
Checking my stats from last night, I averaged a resting heart rate of 50-63, but in the early hours my stats show my heart rate reading with two dots, the bottom at 52, the top dot at 153 - surely that's a glitch?
Heart readings around 155 and flatlining suggest a strap that is too loose
This workout walk shows such an event when I accidentally put on my Watch one hole too loose.
Retightening fixed it.